Apparatus for forming printing sheets in preparation for application to alpha printing cylinder



RINTING SHEETS IN PREPARATION TO APRINTING CYLIN Filed June 28. 1924 M. owEN APPARATUS FOR FORMIN DER G P FOR APPLICATION umwm JIM/Y 1- Patented May 4, 1926.

UNITED STATES APPARATUS FOR FORMING PRINTING SHEETS IN FREIPARATION FORLAPPLICAT ION:

A v 1,583,091 PATENT oFFICE- MALCOLM OWEN, OF LONDON, ENGLAND.

TO A PRINTING CYLINDER.

Application filed June 28, 1924. Serial No. 723,038.

To all whom it may concern:

Be it known that I, MALCOLM OWEN, a subject of the King of Great Britain, residing at 109 Farringdon, Road, London, E. G. 1, England, have invented certain new and useful Improvements in Apparatus for Forming Printing Sheets in Preparation for Application to a Printing Cylinder, of which the following is a specification.

This invention relates to apparatus for forming sheets in preparation for applica-' tion to a printing cylinder of the kind having a gap in which the ends of the sheet are secured, in particular to the forming of etched thin sheets of metal which are applied to cylinders for intaglio and photogravure printlng.

plication Serial No. 692,409 to previously Such etched sheets are of very springy nature, and accordingly very ditficult to manipulate. However, in Patents No. 1,l58,- 4:77 and No. 1,478,947 there is described and claimed a method and apparatus respectively for applying sheets directly to their printing cylinders, the method consisting in attaching one end of the sheet on one side of the gap of the printing cylinder, and stressing the sheet mechanically under tension tangentially to the cylindrical surface, the cylinder being held against rotation during the initial straining, and then while the strain is main-' tained, rotated to wrap the sheet tightly around it, whereon the other end of the sheet is fixed within the gap. By such a process the sheet is found to be absolutely evenly bedded on the surface of the printing cylinder. p

In printing it is always necessary to provide a proof, and accordingly labor and time are lost in applying the sheet to the printing cylinderin order to take off one or a few prints, because this necessitates the removal of the cylinder from the printing machine in order to be put into the apparatus, operating as described above, so as to apply the sheet thereto, and then replace thecylinder with the sheet in the printing machine. The proofs having been taken, the sheet is'removed so as to leave the cylinder applicable for other printing processes.

In order to avoid the necessity of removing the cylinder of a printing machine, it has been proposed by this applicant in apform the sheet on a segmental former so that when taken therefrom it is ready for immediate application to the cylinder, the ends i of the sheet fitting the walls of the gap, the method of forming the sheet consisting in cutting the sheet to correct length, stressing the sheet, and while the stress is maintained, bending the sheet over sharp edges of the segmental former spaced apart by a convex segmental surface thereof, which surface is of a length equal to the circumference of the printingcylinder less the width of the gap, so that as a continuous operation first one end of the sheet is folded over and the sheet'bent, and then the other end folded over, the spacing and forming of thefold being such'thatit will coincide exactly with the longitudinal edges of the cylinder gap when the sheet is applied to the cylinder.

In the accompanying drawings is illus trated a preferred construction of apparatus according tothe present invention. 1 Fig. 1 is a side elevation of the unit apparatns;

Fig. 2'is'a plan view of the construction shown in Fig. 1 with parts removed and parts in section for sake of clearness;

Fig. 3 is'an enlarged view of a detail comprising the" construction shown in Figs. 1

inder for only a part of the height of the gap, and then diverged so that the outer part of the gap is tapered toward the centre of the cylinder. This form of cylinder is used with a wedging piece which fills the gap and secures the ends of the sheet within it.

As this cylinder construction forms no part of the present invention no further descript-ion will be given thereof.

Referring to the drawings 1- indicates the former, which is/hereafter more fully described, upon which. it is desired to wrap a metal printing sheet under tension. 'The former runs in bearings 2 onthe support including framework 3, on which is mounted uprising supports 3 and its rotation is effected by a train of driving pinions and driven wheels e. g., 5, 6, 7 8, the first pinion 5 being rotated by a pulley 9 or the like. By reason of the gear ratios, unless rotated by the pulley 9, the proportions are such that the former 1 will be held stationary against rotation even though subjected to a consider- .to the former along which the sheet is stressed when the former is rotated with the tension applied. The sheet 10 (Fig. 2) itself is connected by means of a cable 12 with a rotatable member 13 in the form of a pulley about which the cable may be coiled, which in turn is connected with friction drums 14, 15 riding loosely on shaft 16 and having the drum 15 fixed to spur wheel 17, the latter in gear with pinion 18 on an intermediate parallel shaft 20, these shafts 16 and 20 being carried in bearings on the supports 3 and, therefore, at a fixed distance from the bearings 2 aforesaid. The pinion 18 is turned by means of hand wheel 19, and, when free, the driving pulley 13 can therefore, be rotated by the action of the g'earpair 17, 18 connected thereto.

The means by which friction isapplied to drums 14, 15 to strain the sheet 10 when secured to the former 1 includes a pair of weighted levers 21, 22 carrying weights 23, 24 and provided at their-opposite ends with sleeves-25, 26 respectively having extensions 27, 28 upon which are keyed'operatinglevers 29,30 extending downwardly from the said sleeves so as to be within reach of atreadle mechanism 31 which will be described hereafter.

As shown in dotted, lines in Fig. 1, and referring only totheweight lever 22, (as

, the lever 2l is identically arranged and associated) the connection between the lever 22 andthe brake drum 15 is achieved by a lever-0r crank 40 fixedly mounted on the lever 22 at one endof a given diameter-of the"d'rum 15 and connected by means of links 41, 42 with arms or straps 43, 44 which;

partly, encircle the drum 15; when allowed,

- these, arms 43, 44 are drawn tightly on, and

embrace, the drum 15 by theweight on the lever221drawing together the links and con,

sequently the' arms to prevent rotation of said drum; the arms arehingedly connected by means of a link 45 at the other end of the said given diameter.

' Inorder that the apparatus, may be easily controlled by one operator an arrangement including treadle gear is provided by which the friction applied to the brake drums. 14

and 15, through the weight levers 21 and 22, is regulated.

The treadle gear consists of the treadle 31 attached to a cross spindle 32, a pair of arms 34 attached to a second cross spindle 33 and provided with rollers 34" disposed so as to bear on the ends of the levers 29,30 andto depress same under, certain circumstances. The connection between the shafts 32'and 33 is preferably made by the levers 355, 36' and thelink 37, see Fig. 1, but obviously. may be by wheel and pinion.

Referring now to -the construction shown in Fig. 4 a former of segmental section as described in my co-pending application Serial No. 692,409, is shown comprising a convex surface 50 which is equal in length to the circumference of the printing cylinder to which the sheet, when formed, isto be applied less-the width of the gap. At the ends of the convex surface there are inclined fiat faces 51, 52, each forming an edge with the convex surface, and each disposed to include between it and the convex surface an angle equal to the angle between the cylindrical face of the cylinder and the contigu? ous part (the tapered part) of the walls of the gap, and these faces 51, 52 are equal in length to the tapered parts of the said walls. Each face 51, 52 terminates at the end away from the convex surface in a flat face 53, 54 respectively making edges. therewith, and these faces 53, 54 are set at an angle to the contiguous faces 51,52 respectively-so that the angle included between them is equal to the angle between the tapered part of the wall and the contiguous vertical part of the wall of the gap. v

In operation the treadle 31 is depressed which causes, through the agency ofthe by the action of the'respective links 41,

connectedbetween the cranks and the arms, thereby retracting the arms and removing the retarding friction from the drtuns14, 15 leaving them free to -rotate, it being understood that the weighted levers 21, 22 are also lifted. At this moment rotation of the hand wheel 19 actuating the pinion and wheel 18,. 17 is available to rotate the driving pulley, 13. If then the sheet 10 is connected by means of the cable 12 with'thedriving pul-- ley 13 the latter canberotated,'-and the other end of the sheet attached to the face; 54 ofthe former, assuming it is placed in its bear.- ings in the position shown in Fig. 4; the cable is wound up on the pulley 13 and eventually a preliminary tensionis applied to the cable and thesheet, so that allplay, on its connecting pins and the likean-dsome part of the slack in the. sheet may, be re. moved before the sheet is :subjectedto the tension proper due to the rotation of the former 1 against the friction applied'bythe- I then in proper condition for applying to the printing cylinder (having aperiphery equal in length to the convex surface of the former) on the printing machine proper.

The means of connecting the sheet to the face 5a of the former will correspond to the manner of connecting the similar end of the sheet in the Wall of the gap] Supposing,

therefore, pegs are used in the cylinder gap, similar pegs 55 Wlll be formed on the face 54, in which case the sheet has to be slotted in order that the pegs may form anchors for the sheet on the face f.

The faces 51 and 53 of the former may be formed on an'integral part thereof, or may or is a continuation of, the convex surface of the former; By using an interchangeable part, such as 56, the effective length of the convex surface of the former may be varied by substituting a portion having a different length of continuation surface, so that the said former may be used in the preparation of sheets for cylinders of various diameters.

By substituting weights of difierent sizes for the weights 23 and 24 the friction on the drums 14 and 15 may be adjusted.

The result of using the present invention is that instead of needing to move a cylinder and sheet from the mill only the sheet thereon need be moved for printing or other purposes, and a unit apparatus is obtained in which a printing sheet can be completelyformed in preparation for applying it to a printing cylinder.

I claim 1. Apparatus for forming printing sheets in preparation for application to a printing cylinder having a gap comprising the combination with a support, of bearings on the support, a former of segmental section rotatably carried by the bearings the convex surface of said former terminating at each end with a sharp edge, the convex surface being equal in length to the circumference of the printing cylinder less the width of the gap, gearing for rotating said former, a tensioning device fixed on the support and spaced from the bearings, fastening means for attaching one end of a printing sheet to the tensioning device, anchoring means for detachably connecting the other end of said sheet near one sharp'edge of said former, and means for preventing reverse rotation of said former under effort from the tensioning device, the arrangement being such that on rotation of the said former through 360 the sheet is wrapped thereon and both ends are bent over the sharp edges'thereof, whereby the ends of the sheet are ready for immediate fixing in the gap of the said printing cylinder.

2. Apparatus for forming printing sheets bination with a support, of hearings on thesupport, a former of segmental section r0 tatably carried by the bearings the convex surface of said form-er terminating at each end Witha sharp edge, theconvex surface being equal in length to the circumference of the printing cylinder less the width of the gap, gearing for rotating said former, a tensioning'device including a rotatable member carried by said support at a fixed distance from the said bearings, a brake drum carried by said rotatable member, adjustable fric tion means operating with said brake drum, connecting means having one end fixed to said rotatable member and adapted to be coiled thereon and at the other end fastening means forattachment to one end of a sheet to be wrapped on a cylinder, anchoringjmeans for detachably connecting the otherend of said sheet near one sharp edge of said former, and means for preventing reverse rotation of said spindle under effort from said tensioning device, the arrangement being such that on rotation of the said former through 360 the sheet is wrapped thereon and both ends are bent over the sharp edges thereof, whereby the ends of the sheet are ready for immediate fixing in the gap of the said printing cylinder.

3. Apparatus for forming printing sheets in preparation for application to a printing cylinder, comprising the combination with a segmental former, of a rotatable member spaced parallelly therefrom, means for connecting one end of the sheet to the segmental former and means for connecting the other end thereof to the rotatable member for straining the sheet between said former and member, manual means for turning said member for applying an initial strain to' said sheet, a friction brake drum movable with said rotatable member, straps co-operating with said drum, weights for applying said straps to said drum, a treadleand operating lever for retracting the straps from said drum, means for preventing reverse rotation of said former under strain from said tensioning device, and gearing for rotating said former when said straps arev applied, whereby on rotation of said former through 360 a sheet wrapped thereon has its ends formed ready for application to a printing cylinder. i

4. The combination With a rotatably mounted segmental former having means for removably connecting one end of a sheet thereto, of a wheel member, means wound thereon forming part of a connection between the wheel and the other end of the sheet, the wheel member being spaced from said former to permit the sheet being strained between them, a friction brake, including a. drum and a pair of hinged straps,

associated -Witl11SfiildJa wlleelpfii roeking; shaft; links pivotal-13m" connected) to said shaft; and to: thefree; ends; of-swidr bnaken stnmps,;,m Weighted, bell ,cra-nk 1 pivoted; by said rocking; 1' shaft;.saidbweight: acting to ro-ekvthecslmfta so as to apply: thestrapsvt-o-r the; brake; andtl'eazcl-le' gear for tilting, seid;-- bell crank: againstv said- Weight, thereby roe-king thesh-aft i to retract; thevbra-ke straps; means for" rotating; said; former-- against said friction:

brake; and means-:for' preventing reverse rotatlonof Silld'fOI-IHGI, whereby onrotatlon-of saidrfo-rmer: through; 360;? a" sheet Wrapped-- thereon has its, end sgformed reedy foraeapplt;

'* cation; to w-printi-ng; cylinder; c

5.1 A2 rotatable segmental former} for pref pat-r1 11g a 1 printing; sheet =f01-" immediate applioation; to a printing; cylinder; having a gap; the: wells of the; cl'ivetgingqatz. the;

outerzpartathereof, eoxnprisingmconve-x surface of: a? length equal-ltoi-the :cirou-mfeizenees of the printing cylinder: to Wlnch the: 81186131 isfto beappliedv less the-Width of'the gag-A a; flat: surface. co-nt-iguonszj-to theconvex surface; ateaclfend' thereof fonming a-nwed'ge Withthe convexsurfaee; the flat sun-faces? each in? cluding: between them: and the convex surface an angle epproXima-telyequal, to theanglebetWeenpth-e (gylindrieel-l face of theprinti-ngcylinclervto which the-sheet is tobe, applied and the contiguous part. of the Walls: of the cylinder-gap, eachz lsaid flat surface terminating atthe'end away: from the-cone vex surface, in a second fiat: SUIfEICBgBHCll set-3 to its contiguous fiat: surfaceeat-v anengle equal; to the; angle contain-ed betweenytwo such surfaces" in the Wail-lei ozf-a the-gap of the? printing cylinder to which the sheet? isvtosbe applied, andw'conneoting; n1eansy-on-=one of StUld rSGCOIId'; fiat surfaces for. attaehing; oneend .offa print ing sheet thereto;-

Intestimony whereof l'aflixfimy signature.

MALGOLMOWEN; 

